Spring (season)Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the spring (or vernal) equinox, days and nights are approximately twelve hours long, with daytime length increasing and nighttime length decreasing as the season progresses until the Summer Solstice in June (Northern Hemisphere) and December (Southern Hemisphere).
Prunus mumePrunus mume is a Chinese tree species classified in the Armeniaca section of the genus Prunus subgenus Prunus. Its common names include Chinese plum, Japanese plum, and Japanese apricot. The flower, long a beloved subject in the traditional painting and poetry of Sinospheric countries (including China, Korea, Vietnam, and Japan), is usually called plum blossom. This distinct tree species is related to both the plum and apricot trees. Although generally referred to as a plum in English, it is more closely related to the apricot.
Four Pillars of DestinyThe Four Pillars of Destiny, as known as "Ba-Zi", which means "eight characters" or "eight words" in Chinese, is a Chinese astrological concept that a person's destiny or fate can be divined by the two sexagenary cycle characters assigned to their birth year, month, day, and hour. This type of cosmological astrology is also widely used in both South Korea and Japan. Four Pillars of Destiny can be dated back to the Han Dynasty, but it was not systematic as it is known today.
ZhuanxuZhuanxu (Chinese: trad. , simp. 颛顼, pinyin Zhuānxū), also known as Gaoyang (t , s 高阳, p Gāoyáng), was a mythological emperor of ancient China. In the traditional account recorded by Sima Qian, Zhuanxu was a grandson of the Yellow Emperor. At the age of ten with Shaohao, he was said to have led the Shi clan in an eastward migration to present-day Shandong, where intermarriages with the Dongyi clan enlarged and augmented their tribal influences. He also was associated with a religious reform of the Jiuli(九黎) people, banishing witchcraft practised by the people.
Korean New YearSeollal () is a traditional festival and national holiday commemorating the first day of the lunisolar calendar. It is one of the most important traditional holidays for ethnic Koreans, being celebrated in both North Korea and South Korea as well as Korean diaspora all around the world. Seol, written as (설) in Middle Korean in Hangul, means "year of age" since it is also the date when Koreans grow a year older. The modern Korean word for "age" – sal is derived from the same origin as seol.
Heavenly StemsThe ten Heavenly Stems or Celestial Stems () are a Chinese system of ordinals that first appear during the Shang dynasty, c. 1250 BCE, as the names of the ten days of the week. They were also used in Shang-period ritual as names for dead family members, who were offered sacrifices on the corresponding day of the Shang week. The Heavenly Stems were used in combination with the Earthly Branches, a similar cycle of twelve days, to produce a compound cycle of sixty days.
History of trigonometryEarly study of triangles can be traced to the 2nd millennium BC, in Egyptian mathematics (Rhind Mathematical Papyrus) and Babylonian mathematics. Trigonometry was also prevalent in Kushite mathematics. Systematic study of trigonometric functions began in Hellenistic mathematics, reaching India as part of Hellenistic astronomy. In Indian astronomy, the study of trigonometric functions flourished in the Gupta period, especially due to Aryabhata (sixth century CE), who discovered the sine function.
